Carburetor



Patented May Y5, 1931 UNITED STATES PATENT OFFICE CARL BREER, OFDETROIT, MICHIGAN, ASSIGNOR TO CHRYSLER CORPORATION, F HIGHLAND PARK,MICHIGAN, A CORPORATION ,OF DELAWARE CARBURETOR.

Application filed VMay as,

This invention relates to carburetion and more particularly to ameans-for enriching the fuel supplied'to an internal combustion enginewhen starting.

When starting or warming up a cool engine it is often desirable toenrich the mixture. This is usually accomplished by the use of a chokewhich cuts off the amount of air supply increasing the suction on thecar- 1Q buretor nozzle and thereby supplying more fuel through thenozzle.

The present invention provides a means for an additional supply of fuelwhen the choke is closed. This additional supply of fuel la is atomizedwhen it reaches the main body of the carburetor thus producing an idealrich mixture.

One of the objects of the invention is to provide a means for supplyingadditional 2c fuel dependent on the amount of suction as determined bythe use of a choke.

Another object is'the construction and arrangement of parts whereby theflow of the mixture is opposed by the velocity of the air passingthrough the carburetor when theair inlet thereof is open. As onepractical adaptation for accomplishing this result, a

passage for directing the fuel into the mixing chamber, is angularlypositioned so that 3c the air velocity may oppose the flow of mixturethrough this passage during normal operation of the carburetor7 and sothat suction created between the choke and throttle, when the carburetoris conditioned for starting, may feed fuel from said passage.

These and other objects will more fully appear from the followingspecification and claims taken in connection with the accompanyingdrawing, in which:

. The figure shows a sectional view of a cari buretor showing theapplication yof the device Referring to the drawing the reference Vnu.-

meral 2 indicates a carburetor body ,provided with the usual float orfuel reservoir chamber 4, mixing chamber 6 and throttle passage 8. Thefloat chamber 4 is shown provided with a fuel inlet 10 regulated by aneedle valve 12 and float 14 of the usual construction. A passage 16leading from the float chamber 4 communicates with the mixing 1926.Serial No. `111,892.

chamber 6. A nozzle 18 is shown as an extension of the passage 16 foratomizing the fuel under suction through the throttle passage.` Theusual venturi 2O for increasingr the pull on` the fuel is shown andathrottle valve 22 is shown to regulate the amount of atomizedV fuel tobe supplied to an internal combustion engine.

Air is Vsupplied to the mixing. chamber 6 throughthe opening 24. A chokevalve 26 is 60 shown adapted to cut off the supply of air, when closed,to increase the suction onV the nozzle 18. It will be understood thatunder running conditions, with the choke lin an open position, theproper proportions of air and gasoline are supplied to the manifold iand engine, not shown; but when the choke isclosed and the amount of aircut off, as in starting a cold motor, a rich mixture is supplied notsufficiently atomized` due to the insuflicient supply of air.

The present invention aims to overcome this difhculty by supplying arich atomized fuel tothe mixing chamber thereby reducing the suction onthe nozzle and consequently supplying a rich, highly atomized fuel tothe engine whenthe choke is closed rather than a poorly atomizedmixture. I

As one desirable means of accomplishing this result a well 28 is shownVadjacent the so ioat chamberprovided with an opening 30 for theadmission of fuel. level is an enlarged portion 82 and leading therefromis an opening or vent 34 opening to atmospheric pressure which may bepro- 85 tected against the admission of dirt by a cover or protection36. A passage shown as a tube 38 leading from the enlarged portion 32 ofthe well opens into the mixing chamber. The opening in this tube islarger than the vent 34 andV asthe suction is increased in the mixingchamber, a vacuum is v.formed in the enlarged portion 32 wherebygasoline and air are drawnvthrough the tube 38first being atomized inthe enlarged portion 32 by 95 a turbulent action; the latter` forming asecondary mixing chamber.

The tube 38 is shown downwardly inclined at a predetermined angle andits discharge end is located in the path of the air which 1w Above thefuel l is admitted through the opening 24twhen the choke 26 is open asto oppose the flow of mixture through the tube 38 when the choke isopen, The location of the discharge end of the tube 38 also causes amixture of fuel and air to be fed from the chamber 32 to the mixingchamber 6 by the suction Which is created in the mixing chamber when thechoke 26 is closed.

In the operation of the device, upon closing of the choke 26 and withthe throttle 22 partly open when starting, a vacuum is created in themain body of the carburetor suiiicient to pull fuel and air through thetube 38 enriching the mixture to the engine with a fuel highly atomized.Due to the added enriching the engine Will start more easily givingsmoother` running and more flexibility during the Warming up period.

It Will be obvious that various changes may be made in the arrangement,combination and construction of the various parts of my improved device,without departing from the spirit of my invention and it is my intentionto cover by my claims such changes as may be included Within the scopethereof.

What I claim is:

1. In a carburetor comprising a float chamber, a mixingchamber providedwith an inlet for the admission of air, means for supplying fuel fromsaid float chamber to said mixing chamber, a Well open to atmosphericpressure for receiving a supply of fuel from said float chamber, anenlarged portion in said Well and above the fuel level, a passage havingan opening larger than the opening to atmospheric pressure andconnecting said enlarged portion and said mixing chamber, and a choke,the outlet of said passage being` in the path of the air admittedthrough said inlet When said choke is open for opposing the flow of fuelthrough said passage.A

2. In a carburetor comprising a float chamber, a mixing chamber providedwith an opening for the admission of air, means for supplying fuel fromsaid float chamber to said mixing chamber, a Well communicating withsaid float chamber and open to atmospheric pressure for receiving asupply of fuel, a tube having its discharge end located for thereception of the air admitted through said openings so that the velocityof the air passing through the carburetor may oppose the iioW of mixturethrough said tube, from said Well to said mixing chamber and means forrestricting` the flow of air to said mixing chamber.

3. In a carburetor comprising a main mixing chamber and a fuelreservoir, a fuel nozzle in said mixing chamber communicating With saidfuel reservoir, an auxiliary mixing chamber having a restricted airinlet there- 1n, and an auxiliary fuel inlet in said main mixing chambercommunicating With said auxiliary mixing chamber, the discharge end ofsaid auxiliary fuel inlet being larger than said restricted inlet andlocated so as to build up a back pressure in said auxiliary mixingchamber when the flow of air through said main mixing chamber is capableof feeding sufficient fuel from said fuel nozzle.

4. In a carburetor comprising a mixing chamber having an air inlet andan air outlet, a source of fuel, a nozzle in said mixing chambercommunicating with said source of fuel, a choke valve in said air inlet,and means communicating With said source of fuel for injecting air andfuel into said mixing chamber when said carburetor is conditioned forstarting, said means being adapted to be rendered inoperative by the airadmitted through said inlet when said choke is open.

CARL BREER.

